// Benke pdf. C6 p15.

#include <stdio.h>
int main()
{
    int i, b, k = 0;
    for (i = 1; i <= 5; i++)
    {
        b = i % 2;
        printf("\n>>>%d,%d", k, b);

        while (b-- >= 0)
            k++;
        printf("\n%d,%d", k, b);
    }
    printf("\n%d,%d", k, b);
}